Piston for gas-engines



H. FILLING.

PISTON FOR GAS ENGINES.

APPLICATION FILED IUNE24 1919.

Patented June 29, 1920.

of severe bending stresses.

UNITED STATES HENRY PILLING, 0F CHORLTON-CUMQI-IARDY, VENGLYAND.

PISTON FOR GASPENGIIVES.

Specification of Letters Patent.

Patented June 29, 1920.

Application filed June 24, 1919. Serial No. 306,508..

To all whom it may concern:

Be it known that I, HENRY PILLING, a subject of the King of Great Britain, residing in Chorlton-cum-Hardy, England, have invented a certain new and useful Improved Piston for Gas-Engines, of which the following is a specification.

In large gas engines the usual hollow water-cooled box piston has hitherto been very liable to fracture due to the existence The usual method of stiffening and strengthening the piston has been to thicken the metal and to em loy internal ribs.

ccording to the present invention, a system of internal ribs is adopted, in which the ribs are so arranged as to be subject mainly to direct compressive and direct tensile stresses instead .of as hitherto usual, to bending stresses. To accomplish this internal ribs are provided as struts rather than as beams or cantalivers, with a result that the full cross sectional area of the rib is uniformly stressed throughout instead of being subject to minimum and maximum stresses as in the case of ribs subject to bending. The liability of hair fractures commencing at the points subject to maximum stresses, as in the case of ribs subject to bending, is thereby reduced to a minimum.

The internal ribs are, preferably, provided in pairs spaced at equal distances apart, members of the same pair being disposed in closely adjacent parallel or approximately parallel planes. The ribs are arranged diagonally, one rib of each air connecting the front end of the boss 0 the piston with the external periphery at the rear end, while the other member of the pair connects the rear end of the boss with the external periphery at the front end. One set of similarly inclined ribs, consequently, acts as struts adapted to resist the forces exerted on one face of the piston; the other set similarly resists the forces acting on the other face. Each rib transmits a direct thrust through the boss to the shoulder on the piston rod or to the piston nut.

The number of pairs of ribs provided depends'upon the size of the piston.

The arrangement according to the invention allows for the necessary circulation of water throughout the interior of the piston.

In the accompanying drawings which represent an example of a construction according to the invention, Figure 1 is a central longitudinal section of the piston and Fig. 2 a cross section on the line 22 of Fig. 1.

he walls of the piston are shown at A; B is the hollow water-cooled piston rod; 0,, C D D etc., pairs of internal ribs between the boss and external wall of the piston; the ribs of each pair are placed close together and in substantially parallel planes; one rib, for example 0,, of the pair extending diagonally from the boss at the face A of the piston A to'the external wall at the opposite face A ofthe piston, while the other rib C of the pair extends diagonally from the boss at the face A to the external wall at the face A The ribs C 1),, etc. are exposed to compressive forces when the gaseous pressure is exerted on the face A and are adapted to resist the forces tending to bend the piston about its central axis under this condition,

While the ribs 6,, 1),, etc. tend to prevent the piston from bending when the pressure is exerted on the face A Having thus described the nature of. my said invention and the best means I know of carrying the same into practical effect, I

one of said sets of ribs connecting the boss adjacent one end thereof to the external wall of the piston adjacent one end of the latter, and the other of said sets of ribs connecting the boss adjacent its other end to the external wall of the piston adjacent the opposite end of the latter.

2. A piston according to claim 1, in which the ribs extending in opposite directions are arranged in pairs, the members of each pair being disposed in adjacent and parallel, or approximately parallel, planes.

Q r r 1,345,233

'3. A hollow water-cooled piston, comprising a pair of opposed Working faces, an external wall and a boss connecting said faces, and a plurality of ribs connecting said boss and the external wall of the piston, some of said ribs extending between the juncture of said boss with one of said faces and said external wall adjacent oneend of the latter, and others of said ribs extend ing between the juncture of said boss with 10 the other face of the piston and the opposite end of said external wall. 7 y

In testimony whereof I have'signed my name to this specification. e f

HENRY FILLING. 

